Search

In the early stages of radio galaxy evolution, where the nuclear jets reside entirely within the host galaxy, the interaction of an expanding radio source with the surrounding interstellar medium is likely to be the most pronounced. These kpc-scale jets will cause nearby clouds to collapse and trigger starbursts in a direct consequence of radio-mode feedback from Active Galactic Nuclei (AGN). In this thesis, I present the first systematic search for ultraviolet emission signatures from radio source-driven AGN feedback in Compact Steep Spectrum (CSS) radio galaxies. Owing to their characteristic sub-galactic jets (1-20 kpc projected linear sizes), CSS hosts are excellent laboratories for probing galaxy- scale feedback via jet-triggered star formation. The sample consists of 7 powerful CSS galaxies, and 2 galaxies host to radio sources >20 kpc as control, at low to intermediate redshifts (z<0.6). Imaging with the Hubble Space Telescope shows extended UV continuum emission in six out of seven CSS galaxies; with five CSS hosts exhibiting UV knots co-spatial and aligned along the radio-jet axis. Young, massive stellar populations are likely to be the dominant source of the blue excess emission in radio galaxies at these redshifts, hence the radio-aligned UV regions could be attributed to jet-induced starbursts. Lower near-UV star formation rates compared to other indicators suggest low scattered AGN light contribution to the observed UV. Dust attenuation of UV emission appears unlikely from high internal extinction correction estimates in most sources. Comparison with evolutionary synthesis models shows that the observations are consistent with recent (1-8 Myr) activity likely triggered by current or an earlier episode of radio emission, or by a confined radio source that has frustrated growth due to a dense environment. While follow-up spectroscopic and polarized light observations are needed to constrain the activity-related components in the observed UV, the detectio

The Beam Lifetime 3 (BL3) experiment at the National Institute of Standards and Technology, USA, aims to improve the precision of neutron lifetime measurements and will hopefully resolve the inconsistency between beam and bottle measurements of the neutron lifetime by enhancing the precision of this beam measurement. In the BL3 experiment, where protons from neutron decay are detected in a silicon detector, a GEANT4-based simulation was used to model, develop, and optimize the experimental setup. The physics list, used to simulate particle transportation and interactions, was derived from one of the advanced examples of GEANT4 and extended with a screened nuclear recoil model appropriate for low-energy proton-nucleus scattering of protons in silicon. This approach will allow the many applications of the SRIM (Stopping and Range of Ions in Matter) software for modelling these interactions to be expanded into the much more general GEANT4 framework where nuclear and other effects can be included. By using the example in TestEm7/StandardNR, G4BL3/SNR, and the physics list in GEANT4, the energy deposition and backscattering/ transmission of 35 keV protons on a silicon detector are studied. Comparing the outcomes with SRIM and confirming the energy accumulation in GEANT4's numerous processes and its effects on the ratio of various components are being analyzed.

The primary goals of this project are to design and fabricate a custom Scanning Tunnelling Microscope (STM). This STM will be a part of the Ultrafast Microscopy and Magnetism Laboratory and will be used to study sub-picosecond electronic and magnetic dynamics with atomic resolution. The design goals of the STM are to have high vibrational stability, low thermal drift, non-magnetic components in the STM head, and optical access to the tunnelling junction for coupling to THz light. The project has spanned multiple complete design and iterative prototyping cycles for the STM head design initially based on the Pan design. The primary parameters for the STM head design were to minimize mass while preserving rigidity and maximize the first resonant mode frequency. All the components were designed using the Computer-Aided Design software (CAD) Autodesk Inventor and tested for rigidity and resonant modes using Autodesk NASTRAN, a Finite Element Analysis (FEA) software. The tested prototypes were initially 3D printed and then milled out of Aluminum 6061 using Computer Numerical Control (CNC) machines for the final parts. The final aluminum STM head prototype has been designed, fabricated, and assembled. The lowest calculated resonant frequency of the head is 1.12 kHz. The STM head was tested for coarse motion and failed to produce sufficient displacement. The tests with the aluminum STM head led to a revised design for the 3D-printed titanium STM head and have guided the design methods for future designs that make even more use of 3D printing. The titanium STM head is designed and fabricated and is waiting to be assembled and tested.

Microwave-based breast imaging is a developing technique that has demonstrated potential as a method for breast cancer detection. The modality interrogates the breast tissues using low-power non-ionizing microwave radiation and relies on a contrast in the dielectric properties of malignant and healthy breast tissues. Research into this field has been motivated by the low cost and small size of microwave hardware, the large contrast in the dielectric properties of malignant and healthy tissues, and the favourable safety profile of non-ionizing microwave imaging. The modality has the potential to be used for screening in remote and under-serviced communities due to these factors. Two major challenges limit breast microwave imaging. Existing estimates of the diagnostic performance, particularly the diagnostic specificity, are relatively poor due to a lack of accurate image reconstruction algorithms. Additionally, image quality analysis has been limited to evaluations of image contrast and localization error that rely on single-pixel intensities. The lack of informative measures of image quality has limited the development of robust image reconstruction methods in the field of research. This thesis addresses these two challenges through the development of a novel image reconstruction method capable of enhanced physics modelling and through the development of methods, metrics, and specialized phantoms for image quality analysis. Enhanced physics modelling improves the physics model used to reconstruct an image and was observed to improve image accuracy and diagnostic accuracy. The standardized methods, metrics, and phantoms developed for image quality analysis were used to compare various breast microwave imaging systems and image reconstruction methods.

The development of efficient ultrafast laser sources based on Yb-doped crystals is very important for a variety of optical applications such as nonlinear spectroscopy, nonlinear microscopy, telecommunications etc. A powerful and high beam quality (near diffraction limited: M2~1) pump laser is desirable to mitigate the effect of reabsorption loss that Yb-doped crystals exhibit and realize highly efficient operation in both continuous-wave (CW) and pulsed domains. Unfortunately, there are no commercially available laser diodes that can provide both high beam quality and high output power (>1 W) simultaneously. This thesis presents the development of a powerful and high beam quality pump laser and then utilizes this pump laser to demonstrate the efficient operation of Yb:YAG laser in CW domain and Yb:KGW laser in both the CW and pulsed domains. In the first part of the thesis, a high-power compact CW Nd:YAG laser was built with greatly improved beam quality operating at 946 nm. A maximum output power of 9.98 W with beam quality factor M2 ~ 5 was obtained. I also demonstrated a highly efficient and tunable CW Yb:YAG laser pumped by the developed Nd:YAG laser. The maximum CW output power of 4.37 W was obtained at 1030 nm with optical-to-optical efficiency of 70% with respect to the absorbed pump power. Wavelength tuning of Yb:YAG laser was then explored due to metrological applications such as references for high-resolution spectroscopy or dimensional metrology. The laser produced a continuously tunable operation over 100 nm from 1000 nm to 1100 nm. This is the most tunable laser among bulk crystalline Yb:YAG solid-state lasers. Due to the increasing interest in dual-wavelength (DW) operation for the use as an optical source for terahertz (THz) radiation, this thesis also gave a demonstration of DW Yb:YAG laser operation. This is the first demonstration of DW operation of Yb:YAG laser pumped by a Nd:YAG laser at 946 nm. The latter part of the thesis concentrated on devel

The objective of this thesis is to quantitatively detect ochratoxin A (OTA) in Canadian grain by electrochemistry. To this end, two distinct sensing approaches were developed. In the first approach, a simple label-free sensor was designed to detect OTA. The oxidation mechanism of OTA was investigated using cyclic voltammetry (CV), and the impact of pH on the sensor's response to OTA was explored. Experimental design techniques were employed to optimize the analytical signal. OTA was successfully detected in wheat extracts using differential pulse voltammetry (DPV). The calculated analytical limit of detection (LOD) and limit of quantification (LOQ) were 57.2 nM and 190.6 nM, respectively. For the second approach, a gold electrode (GE) was modified with an OTA-specific aptamer to create a selective aptasensor. Methylene blue (MB) was linked to the aptamer, and the cathodic peak resulting from the reduction of MB at the aptasensor's surface was recorded as the analytical signal using square wave voltammetry (SWV). The surface packing density of the sensor was calculated to optimize the OTA aptamer concentration during sensor modification. The proposed aptasensor detected OTA in phosphate-buffered saline (PBS) media with a lowest measurable concentration (LMC) of 3.44 µM and a lowest quantifiable concentration (LQC) of 10.42 µM. The aptasensor demonstrated its capability to detect OTA in spiked wheat extracts with acceptable accuracy. The thesis concludes by comparing the two developed methods and discussing future research opportunities to enhance the performance of the aptasensor.

We designed and implemented a hyperspectral microscope with structured illumination using the Olympus IX73 microscope as its basic platform. This system, which was designed and built in our Integrated Computational Optical Imaging Laboratory, combines two Digital Micromirror Devices (DMD) to compensate for the angular dispersion introduced by the blazed grating structure of the original DMD that was used to produce the structured illumination. Our hyperspectral microscope uses a supercontiuum laser illumination that can be spectrally filtered for desired wavelength ranges using an acoustic-optic filter. The system is controlled using LabVIEW, that allows for synchronous and asynchronous control of 1) illumination laser source, 2) acousto-optic filter, 3) spatial light modulator (DMD) and 4) camera. This LabView-based system control enables the implementation of a wide variety of image acquisition modes. Our microscope’s hyperspectral modality uses a wavelength-scanning configuration, where the supercontiuum laser illumination is filtered using an acousto-optic filter to produce very narrowband light for to acquire different hyperspectral images. Our system could be an excellent platform for implementing different types of hyperspectral data acquisition to implement, e.g., super-resolution microscopy and compressed sensing. The use of a DMD-based spatial light modulator allows for very fast spatial light modulation.

This work investigates the localized control of magnetization reversal in square artificial spin ice (SASI) systems through the introduction of vertical control elements (VCEs). This research focuses on the effects of localized magnetic fields created by VCEs on the magnetization dynamics within SASI. We explore theoretical considerations and implementation strategies for using VCEs to modulate the energy barriers of individual spin flips, thereby influencing the overall magnetization reversal process. Using a single-spin flip Monte Carlo algorithm, we simulate the hysteresis behaviour of a 16-spin SASI system with and without the presence of VCEs. The simulation parameters are chosen to include thermal fluctuations at low temperature and field symmetry breaking. The results demonstrate that VCEs can effectively pin or facilitate the flipping of specific spins, allowing for controlled domain wall nucleation and propagation, mediated by motion of the lattice excitations, known as monopole charges. This control over monopole charge dynamics has potential applications in magnetic storage devices and spintronic technologies. The study provides insights into the impact of the controlled application of localized magnetic fields on the energy landscape of ASI systems.

Biological processes required for life can be understood by studying the underlying molecular and chemical processes which give rise to these biological processes. Proteins are the primary functional molecules of biological systems where they serve as catalysts, cell signaling molecules, receptors and also serve structural and mechanical roles. In order to perform these various functions, proteins must physically interact with other molecules referred to as ligands. Therefore, developing a detailed understanding of protein – ligand interactions from a chemical and molecular perspective improves the understanding of the biological processes which these interactions give rise to. A detailed understanding of these protein ligand interactions also enables the development of drugs capable of disrupting or modulating protein – ligand interactions for the treatment of diseases. In other cases, the study of protein – ligand interactions can be used to develop new and useful biotechnologies. Many techniques can be useful for studying protein – ligand interactions including structural, computational, and biophysical techniques. Of these, biophysical techniques often provide the greatest deal of foundational insight into the nature of the protein – ligand interactions. In addition, a biophysical characterization of a protein – ligand interaction is often a prerequisite for the development of drugs and biotechnological applications for these protein- ligand interactions. Three unique protein – ligand interaction systems are explored in this thesis, using a combination of structural, computational, and biophysical techniques. In the first part of this thesis the interaction between the Laminin N-terminal domain and Ca2+ is explored using a combination of structural, computational, and biophysical techniques. From this approach, a detailed understanding of the molecular basis and functional properties of the interaction between the Laminin N-terminal domain and Ca2+ is developed.

There is a clinical need to develop lipid nanoparticles (LNPs) to deliver prenatal therapies to the developing fetus during pregnancy. The aim of these therapies is to restore normal fetal development and prevent irreversible conditions after birth. As a first step, LNPs need to be optimized for transplacental transport, safety, and transfection efficiency in fetal cells. We developed and characterized a library of LNPs of varying compositions and used machine learning (ML) models to delineate the determinants of LNPs size and zeta potential. Utilizing different in vitro placental models with the help of the Random Forest algorithm, we studied the features driving percentage LNPs transport and kinetics, using a dataset of 18 input features encompassing 48 different transport experiments. We further evaluated the LNPs for safety and transfection efficiency in placental trophoblasts and fetal lung fibroblasts. Finally, we assessed toxicity of the LNPs in a tracheal occlusion fetal lung explant ex-vivo model. LNPs showed little to no toxicity to fetal and placental cells. Immunoglobin G (IgG) orientation on the surface of LNPs, PEGylated lipids, and ionizable lipids had significant effects on placental transport. The Random Forest algorithm identified the top features driving LNPs placental transport percentage and kinetics; zeta potential emerged as one of the top driving features. Building on the ML model results, we developed new LNPs formulations to further optimize the transport leading to a 622% increase in transport. To induce preferential siRNA transfection of fetal lungs, we further optimized cationic lipid percentage and the lipid-to-siRNA ratio. Studying LNPs in an integrated placental and fetal lung fibroblasts model showed a strong correlation between zeta potential and fetal lung transfection and ensured the integrity of the LNPs following transplacental transport. Finally, the optimized formulations appeared to be safe in ex vivo fetal lungs as indicated

The MOLLER (Measurement Of a Lepton-Lepton Electroweak Reaction) experiment aims to measure the parity-violating asymmetry APV in the scattering of longitudinally polarized electrons off unpolarized electrons, using the recently upgraded 11 GeV beam in Hall A at Jefferson Laboratory (JLab). The goal is to reach an overall accuracy of 2.4% for the measured APV, which would be an improvement of a factor of five compared to any other similar experiment to date. This thesis discusses hardware aspects of the design and development of the main detectors for MOLLER, as well as development work towards a new type of electron detector (HVMAPS) that will be used for both the integrating detector and the Compton polarimeter. Prototypes of the integrating detectors were assembled and tested using the 855 MeV beam at the Mainz Microtron (MAMI) in Mainz, Germany. A new mounting structure with an integrated cooling system is being developed for the HVMAPS detectors for the Compton polarimeter.

Massive galaxies are believed to harbour supermassive black holes at their centers, which actively accrete matter and are visible as active galactic nuclei (AGN). A key breakthrough in modern astronomy was the explanation of the sharp cut-off of the galaxy luminosity function, which could not be fully explained without using models that include the energetic feedback from AGN. Consequently, the interplay between the energy released from AGN and their host galaxies has become a popular astronomical research area—now known as AGN feedback. Although AGN feedback has been studied over the last decades, there are still many unknowns. The most common route of AGN feedback is through driving superwinds or outflows, where the ambient gas could be expelled out of the AGN host galaxies. Currently, we lack a proper understanding of how these outflows quench star formation in their host galaxies. Furthermore - (i) the spatial scale on which these outflows operate, and (ii) the driver of these outflows are highly debated, which are the two issues this thesis addresses. I analyze the 1D and 3D spectroscopic data of a rich sample of radio-loud (RL) and nearby (z~0.01-0.06) radio-quiet (RQ) AGN and found that the AGN-driven outflows are usually localized to the central 1 kpc with most of the outflowing gas located at <100 pc from the supermassive black holes. But there are instances where it could be extended on several kpc scales. Whereas AGN radiation could drive these outflows in RL AGN on sub-kpc scales, radio jets are necessary to carry these to several kpc scales in our sample. In RQ AGN, AGN bolometric luminosity does not determine whether the respective AGN will launch a compact (<1 kpc) or extended (>1 kpc) outflows in our sample. Either the radio jets could launch these outflows, or the AGN duty cycle is important in determining whether the outflows will be confined to the central <1 kpc region or traverse galactic distances. Overall, this thesis demonstrates that the ene

There are four fundamental forces within the natural world: electromagnetism, gravity, the strong nuclear force, and the weak nuclear force. One of the primary windows to the inner workings of the weak nuclear force has long been found in observations of beta decay processes. Of particular interest is the form taken by the couplings involved in beta decay; prior experiments have shown that the process is dominated by a combination of vector and axial couplings, analogous to Maxwell's theory of electromagnetism --- however the possibility of a non-dominant contribution from exotic scalar or tensor couplings remains. Such a discovery would shake the foundations upon which our understanding of the weak force is built. A precision kinematic measurement is conducted to search for- or constrain exotic couplings within the nuclear weak force by measuring an observable known as the Fierz interference, $b_{Fierz}$, within the $^{37}$K$ \rightarrow ^{37}$Ar$ + \beta^+ + \nu_e$ transition. The effect, if present, would manifest as a perturbation to the expected shape of the energy spectrum for betas emerging from a decay --- or equivalently, as an apparent change to the energy dependence of the beta asymmetry ($A_\beta$, measured with respect to nuclear polarization), which is the approach employed here. As the observable is comprised of a linear combination of scalar and tensor couplings, any non-zero value of $b_{Fierz}$ would be indicative of exotic physics. The measurement is carried out within the TRINAT laboratory located at TRIUMF, which provides the radioactive $^{37}$K necessary for the experiment. The TRINAT apparatus provides an isotope-specific means to cool, confine, and intermittently spin-polarize $^{37}$K atoms within a magneto-optical trap. Upon decay, outgoing particles are emitted from a small central cloud into an open geometry featuring a variety of detectors. A thorough understanding of the nuclear polarization allows the superratio technique to be employ

This thesis chronicles measurements of ultracold neutrons (UCN) performed at TRIUMF in fall 2018 and fall 2019. Heat response data of the UCN source bottle was taken by measuring its temperature using the vapour pressure of the 4He. The time-dependence of the He-II bottle temperature is well-described by a model where heat transport is limited by quantum turbulence in the He-II. In addition, measurements of UCN spin manipulation components showed that the adiabatic fast-passage device had a spin flipping efficiency of 0.977 ± 0.008 and 1.007 ± 0.008, and the spin analyzers had a measured polarizing power of 0.650 ± 0.003 and 0.630 ± 0.003. Simulations show that the low spin analyzer efficiency is most likely due to a lower than expected magnetization in the foils, and additional sources of depolarization around the spin-analyzers. The simulations of the analyzer show that the single pass polarizing power of the foil is 0.78 ± 0.08. Under the assumption of no transmission of the wrong spin state through the superconducting magnet, the polarizing power was measured as 0.57 ± 0.05. Simulations reveal that the bore was responsible for some reduction in polarizing power, however better magnetic field gradient control for the spin flipper gradient is required to rule out the possibility of inefficient spin flippers as the cause of the depolarization.

An analytic stationary solution for rotating, magnetized, non-self-gravitating filamentary molecular clouds is presented as a model for molecular tornadoes. This model results in monotonically decreasing density profiles for rotating filaments, unlike previous filament models, which suffered radial oscillations in density referred to as density inversions. Whereas previous models consider the effect of self-gravity on molecular clouds, we use estimates derived from observations of the Double Helix Nebula, the Galactic Centre Tornado, and the Pigtail Nebula in the Central Molecular Zone of the Milky Way Galaxy that highly pressure truncated filamentary clouds are at most weakly self-gravitating. The simulation code Athena++ is used to study the time evolution of the model to assess its stability and evolution. Two different sets of boundary conditions are simulated, one which simulates an infinitely long idealized filament and another which simulates a finite filament protruding from a fixed rotating source. Simulations of the model do not develop detectable instabilities until at least twenty-five sound crossing times. However, simulations seeded with white noise with a standard deviation 0.01 in their initial density profiles develop kink instabilities within ten sound crossing times

Massive stars end their lives in a catastrophic explosion known as a core-collapse supernovae (CCSNe). CCSNe explosions leave behind neutron stars, with a known diversity that includes the Central Compact Object (CCO). The nature of the CCO, however, remains a puzzle; in particular it's not clear whether they originate from a specific supernova subclass with a limited mass range. To address their supernova progenitors, we perform a systematic study on SNRs hosting CCOs that show evidence of shock-heated ejecta. We make use of primarily X-ray data obtained with the Chandra space telescope which has unparalleled imaging resolution in the 0.1-10 keV band where SNRs shine brightly. For the larger remnants, we also use the XMM-Newton telescope that has a larger field of view and higher sensitivity to low-surface brightness emission in the 0.1-10 keV band. This study takes a systematic approach to the analysis, where we use an algorithm to segment each SNR into regions of similar surface brightness for a spatially resolved spectroscopy study. These regions are fit by one- or two-component plasma shock model(s) in order to separate the forward shocked interstellar medium from the reverse shock-heated ejecta which peak in the X-ray band for elements O, Ne, Mg, Si, S, Ar, Ca, and Fe. We subsequently derive the explosion properties for each SNR in the sample and find overall low-energy explosions (<10^(51) ergs). In order to address the progenitor mass, we compare our measured abundances to the supernova ejecta yields of five of the most used nucleosynthesis explosion models in the literature and a relatively new electron-capture supernova model. We find that the explosion models commonly used by the astrophysics community do not match the ejecta yields for any of the SNRs. With this caveat, we present our best estimate for the progenitor mass of each SNR in our sample and find overall low-mass progenitors (<=25 solar masses) among the massive stars population. We discuss deg

The Standard Model of Particle Physics is a successful yet incomplete description of matter and interactions in the universe. The rate of neutron beta decay in the decay of free neutrons is sensitive to beyond the standard model physics where the types of interactions are constrained by the Lorentz invariance of bi-linear covariants. Precision measurements of decay correlation parameters can be used to test standard model predictions. The Nab experiment at the spallation neutron source(SNS) Oakridge National Laboratory aims to measure the anti-electron-neutrino correlation \lq a\rq, and Fierz interference term \lq b\rq\:in unpolarized neutron decay to greater precision to date. The Nab collaboration uses large area silicon detectors to measure decay products in free neutron decay. Systematic tests of detector system properties are necessary for any precision detection system. The University of Manitoba group modified the Manitoba 2 mass spectrometer to operate as a low energy proton source to use as a detector test facility for low energy protons. The full Nab detector apparatus was installed and tested at the University of Manitoba in early 2021. The subject of this thesis is the preparation of the Manitoba 2 proton source for detector testing and, the operation and characterization of the Nab detector for 30 keV energy protons. In this work, the corresponding setup, tests and partial measurement results are presented. The measured proton energy in general may depend on detector temperature, radial location of detector pixel and the detector bias current, all of which were investigated. The proton energy was measured for three different accelerating potentials (25 KV, 30 KV, 35 KV). The proton event rate was measured in neighbouring pixel during the proton beam sweep across the pixel boundary.

The interaction between magnons and photons has significant implications for quantum information processing and in spintronics. In an electromagnetic cavity, wherein photons are confined, the photon-magnon coupling can be enhanced and controlled more effectively. In this thesis, we investigate a model system wherein the interaction between an antiferromagnetic domain wall and cavity photons occurs via the inverse Faraday effect, resulting in a coupling analogous to optomechanical coupling. The coupled dynamics leads to the emergence of level attraction, a term used to describe the coalescence of two distinct eigenmodes in a region bounded by exceptional points. We reveal the impact of the Dzyaloshinskii-Moriya Interaction (DMI) on the coupled dynamics of domain walls to cavity photons. We demonstrate that the presence of DMI can affect the coupling between magnons and photons, depending on the geometry of the system. This finding has potential applications in the control and detection of DMI in antiferromagnetic materials. Using a different formalism, we provide a demonstration that the phenomenon of level attraction can arise in systems characterized by instability under non-equilibrium conditions. A formalism for characterizing the linear response of driven magnonic systems has been developed and we show that results can be reproduced using numerical micromagnetics. The developed theory facilitates the study of cavity magnonics using numerical micromagnetics.

Energy differences in nuclei are paramount to understanding the nuclear systems far from stability, their rare decay modes, and trends in their relative stability. Modern ion trapping techniques such as Penning Trap Mass Spectrometry (PTMS), and Multiple Reflection Time Of Flight Mass Spectrometry (MRTOF-MS) have enabled the precision measurement of energy trends in even very short-lived nuclei, by allowing their masses to be measured. Such nuclei can be generated in large quantities at TRIUMF's Isotope Separator and Accelerator (ISAC), and TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN) specializes in measuring the masses of the short-lived species produced at ISAC using an array of ion traps. This thesis describes measurements of the masses of neutron-deficient lanthanide elements produced at the ISAC facility at TRIUMF in Vancouver, Canada using the TITAN Multiple Reflection Time-Of-Flight (MR-TOF) mass spectrometer. The goal of these measurements was to extend the known existence of the N=82 shell closure up to Yb (Z=70), and to experimentally determine the location of the proton drip-line in Tm (Z=69). Mass measurements of 150Yb, 151Yb, and 153Yb confirm the continued existence of the N=82 shell closure. Additionally, new mass measurements of 149Tm and 150Tm were performed, as well as a re-measurement of 149Er that provides a correction to the literature value as published in the 2020 Atomic Mass Evaluation. Together, these mass data points provide the first experimental confirmation that 149Tm is the first proton-unbound species in the Tm isotopic chain. Furthermore, a new technique intended for rapidly cooling highly-charged ions (HCIs) produced via charge-breeding in TITAN's Electron Beam Ion Trap (EBIT) is experimentally tested. This technique involves sympathetically cooling the ions using free electrons, and holds the promise of cooling HCIs on a time-scale of seconds or less for studies with either short-lived or stable species. Technical challe

Artificial spin ice (ASI) systems have emerged as a captivating research field due to their ability to exhibit intriguing properties, including topological defects, magnetic monopoles, and complex spin textures. These systems offer a versatile platform for studying geometric frustration and exploring emergent magnetic phenomena. Moreover, the controllable nature of ASIs holds promise for potential applications in data storage, microwave filtering, and spintronics. ASIs also serve as valuable model systems for understanding the physics of magnetic materials and frustrated systems. This thesis focuses on investigating the accuracy of a machine learning model on ASI materials using the framework of the restricted Boltzmann machine (RBM). RBM offers interpretability within the realm of statistical physics and can effectively analyse and interpret the vast amount of data generated in condensed matter physics experiments and simulations. By leveraging RBM, we aim to gain deeper insights into the behaviour and characteristics of defects in ASI systems. Defects possess unique properties and dynamics that hold potential for information storage, logic operations, and magnetic texture manipulation. Understanding and engineering these defects allow for precise control over the magnetic properties of ASI, including interactions and anisotropy, enabling tailored functionalities for specific applications. This research explores the accuracy and effectiveness of RBM models specifically applied to ASI systems. By utilizing RBM, we aim to analyse and uncover the intricate behaviours and features of defects in ASI, contributing to a deeper understanding of these materials and their potential applications. The findings from this study provide valuable insights into the behaviour of defects in ASI materials and offer avenues for optimizing these systems for desired functionalities. By leveraging machine learning techniques, such as RBM, we can further explore and harness the potential o

The response of the proton to elastic scattering events has long been known to be described via two functions of the squared momentum transfer: the Sachs electric and magnetic form factors Ge and Gm, respectively. To understand the elastic structure of the proton there are two main observables which constrain the form factors: unpolarized cross section data from elastic electron-proton scattering events, and polarization transfer measurements, which generate polarization ratio data. After taking into account tree-level radiative corrections, separate fits of the form factors to these data lead to fits which disagree significantly with one another. Higher loop corrections, especially two-photon-exchange corrections, have been assumed to play a larger role than previously thought in order to explain this discrepancy. We present our global reanalysis which takes special care to treat normalization uncertainties in a most statistically rigorous manner, with additional work done to understand how to extend certain statistical methods only defined for linear models, to non-linear models. We find only minor differences to fits when normalization uncertainty is correctly accounted for. We also present a simultaneous global fit to the two-photon-exchange corrected cross section data and polarization ratio data. In addition to the above, an independent recalculation of the resonance contribution to the F3gz structure function is computed using quark model helicity amplitudes.

About half of the elements heavier than iron (Z = 26) are believed to be formed via the r process (rapid neutron capture process), of which our understanding is limited. Running theoretical simulations to gain insight into this r process rely on the availability of nuclear data (like nuclear masses, beta decay lifetimes, neutron capture cross sections and others) with reduced uncertainties for nuclides near the expected r-process path. Such data is available in limited capacity due to the challenges in producing those exotic nuclides. The astrophysical conditions required for the r process, and the events that generate them are still open questions. The CAlifornium Rare Isotope Breeder Upgrade (CARIBU) at Argonne National Laboratory (ANL) uses the spontaneous fission from a Californium-252 (252Cf) source and is one the few facilities world-wide to produce beams of such neutron-rich isotopes around the mass numbers A = 105 and A = 140. The extracted ions are subject to multiple stages of cooling and purification, before they are sent to the Canadian Penning trap (CPT) mass spectrometer, where their masses are measured using the Phase-Imaging Ion-Cyclotron- Resonance (PI-ICR) technique. The main focus of this work was to provide data on atomic masses that would allow simulations to replicate the rare-earth peak in the observed r-process abundance pattern. Masses of a total of 34 nuclides are presented in this thesis, of which seven were measured for the first time, including the first-time measurements isotopes of Ce (Z = 58): A = 152−155. The results of these Ce isotopes, with their uncertainties reduced from the extrapolated values of ≥ 200 keV/c2 in the latest Atomic Mass Evaluation (AME2020), to ≤ 6 keV/c2, agree with mass predictions from a reverse engineered Markov Chain Monte Carlo technique for a hot r-process environment, hence validating this “hot” r-process model for this mass region.

Time-resolved magneto-optic studies of magnetic materials are of wide interest across the globe today as we constantly search for new ways to push the development of technology forward. The development of technology requires new and innovative characterization methods to determine which materials are worth our research focus. The time-resolved magneto-optical Kerr effect (TR-MOKE) has been a characterization tool applied to study magneto-dynamic phenomena over time-scales down to tens of femtoseconds, known as ultrafast phenomena, since the 1990s. This thesis will present the development a TR-MOKE magnetometer that implements a dual-delay line configuration to obtain resolution shorter than one picosecond for a total delay over ten nanoseconds. The apparatus, which is developed throughout this work, will be capable of measuring spin waves with GHz frequencies down to ultrafast switching phenomena in the THz range, allowing for the investigation of long- and short-time scale magnetodynamic phenomena. This apparatus is additionally designed for versatility. Alterations were made to obtain preliminary time-resolved infrared spectroscopy measurements over nanosecond timescales.

The incorporation of spin dynamics into electronic and optical devices is a promising avenue of technological advancement. This work describes the development of a scanning Fabry-Perot cavity to study magnon-photon with terahertz (THz) light and its application to the measurement of a multiferroic antiferromagnet, Bismuth orthoferrite. The mirrors of this cavity are distributed Bragg reflectors made with alternating layers of silicon and air capable of creating a high reflection, low loss, low transmission for frequencies near 0.555 THz. Resonant frequencies of the cavity are moved across a THz spectral range of 0.5-0.6 THz allowing a search for hybridized magnon photon modes called cavity magnon polaritons (CMPs) (cavity modes coupled with electromagnon modes) in bismuth orthoferrite. Bismuth orthoferrite has known electromagnon modes in the THz region at 0.530 and 0.555 THz. The Fabry-Perot cavity is inserted into a tilted pulse front THz spectrometer and THz time-domain spectroscopy measurements are performed on the suspended Bismuth orthoferrite powder. Resonant frequency peak splitting near 0.530 THz and 0.555 THz is investigated.

Following the development of a Magnetic Resonance Imaging (MRI) compatible small animal Positron Emission Tomography (PET) insert, the University of Manitoba PET lab aims to develop an MRI compatible brainPET designed to retrofit into the Siemens Magnetom 7 T brain MRI. The purpose of this device is to perform simultaneous PET/MRI brain imaging for identification and diagnosis of brain and neck tumours, as well as neurodegenerative diseases. This thesis focuses on finding a suitable detector block through experimentation to be replicated 64 times to make up 4 rings of a 35 cm diameter brainPET insert. Experiments are conducted with a detector block and timing pick-off detector setup to capture 511 keV annihilation photon pairs emitted by a 22Na source, using the PETsys TOFPET2 ASIC for signal readout and digitization. The detector block is a Dual-Layer Offset (DLO) array of 2.4 mm pitch Lutetium-Yttrium Oxyorthosilicate (LYSO) scintillator crystals optically coupled to a sparse array of 3 mm Silicon Photomultiplier (SiPM) photosensors, with a 21 % fill factor. Motivating the low fill factor is the reduced cost of the detector, however it leads to scintillation light loss over the dead space on the photosensor board. To minimize light loss, reflective materials are placed on the board and tested, including Enhanced Specular Reflector (ESR), and white Polylactic Acid (PLA). The best result was with the PLA reflector, with a per-crystal average energy resolution of (18.5/19.0)% at 511 keV and Coincidence Timing Resolution (CTR) of (0.83/0.82)ns FWHM for the top/bottom layers of the scintillator. Lightguides promoting crystal-photosensor lightsharing were tested by calculating the resolvability of scintillator crystal positions measured by the detector. Of the lightguides tested, the 1.5 mm and 2.0 mm thicknesses produced the best crystal resolvability. Data processing techniques used for analysis are discussed, and parameters are tested by their effect on the results.

Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer death for women in Canada. Access to breast cancer screening is limited in northern and First Nation communities in Canada, as well as low- and middle-income countries (LMIC) in the broader international community. Lack of accessible screening tools contribute to inequitable care and increased mortality rates. Microwave breast detection has shown promising results as a safe, low-cost breast cancer screening method. This thesis aims to design and simulate a portable microwave device suitable for use in remote and low-income areas. The device features a cylindrical array of patch antennas and, through machine learning, will require no trained personnel to operate or obtain a preliminary diagnosis. Tiny vector network analyzers were used to measure S-parameters from 0.7 - 3 GHz. A basic radar model was improved to incorporate spherical spreading, microwave attenuation, and secondary scattering. This radar model was used to simulate time-domain sinograms of dual rod models. The rod models consisted of two point scatterers with assigned reflectivities of 100% & m% or m% & m%, where m was varied as: 10%, 30%, 50%, 70%, and 90%. The simulated sinograms were used to train a convolutional neural network to locate the rod responses. The network was able to easily detect and locate the 100% rod response, but struggled with the lower 10% and 30% reflectivities. The 100% and 90% rod models performed with an accuracy of 92%. The use of machine learning improved upon conventional reconstruction methods for breast microwave radar. Similar machine learning techniques can be performed on real scans with shell-based breast phantoms. The radar model simulations can be used to increase the data set size and improve training performance through transfer learning. Microwave sensing and machine learning methods offer promising possibilities to breast cancer screening accessibility for women in remote and lo

Artificial spin ice consists of patterned arrays of interacting ferromagnetic nanomagnets. By exploiting the interactions between the individual elements, we can realize some fascinating behavior of these arrays to create new functionalities. Also, advancements in lithographic processing and film growth have enabled the creation of more complex structures by going beyond two-dimensional designs. This thesis is a numerical study of field-driven dynamics in the bilayer artificial spin ice (BASI) system in which the layers are twisted with respect to each other. The goal is to understand how magnetization dynamics are affected by adjusting the layer separation and layer rotation. We study the square and pinwheel geometries of bilayer artificial spin ice and compare outcomes. The initial segment of this thesis is an analysis of the interaction energy between the layers as a function of layer separations and layer rotations to better understand how the energetics of the bilayer artificial spin ice system are affected by interlayer coupling strength. This work also addresses magnetic field-induced vertex dynamics in square and pinwheel BASI. A numerical study of magnetization reversal processes in BASI systems under the influence of a uniform magnetic field reveals the nature of low energy states that appear during the process. The effect of layer rotation on the vertex dynamics of the system is also investigated under different orientations of the field. The final part of this thesis is dedicated to the study of thermally driven dynamics in BASI to explore the low-temperature steady states available to these systems. The aim is to look for low-temperature ordering that might arise in BASI systems and to investigate how it changes for different layer separations and layer rotations. The results presented here demonstrate that bilayer artificial spin ice can serve as a playground to study the out-of-equilibrium dynamics owing to its increased degrees of freedom. Bilayer ar

The CREX experiment measures the 48Ca neutron radius using an electroweak probe. To run the experiment after PREX-2, which measures the neutron radius of 208Pb with the same electroweak parity violation technique, without a configuration change of the equipment, the septum magnet needs to meet field requirements suitable for CREX. As the magnet is iron-dominated the field response is non-linear at sufficiently high current. This is of particular concern for CREX which is run at a beam energy more than double that of PREX-2 and requires a large septum current to provide the specified bend radius. To determine it's suitability in the experiment the magnet non-linearity must be characterized. To that end, the magnetic flux density was simulated using finite element analysis software and was analyzed in the high-field regions and the zero-field region of the septum. In this thesis I will show evidence of magnetic saturation in the septum magnet at the CREX current and that the requisite field strength can be attained in the magnet gaps. I will also show that the proposed upstream and downstream extensions of the beam pipe shield reduce the maximum fringe field strength by more than 80% and provide a factor of 10 improvement to the maximum field integral inside the beam pipe region.

Holography offers a vital platform for optical information storage and processing, which has a profound impact on many photonic applications, including 3D displays, LiDAR, optical encryption, and artificial intelligence. In this review, we provide a comprehensive overview of optical holography, moving from volume holography based on optically thick holograms to digital holography using ultrathin metasurface holograms in nanophotonics. We review the use of volume holograms for holographic multiplexing through the linear momentum selectivity and other approaches and highlight the emerging use of digital holograms that can be implemented by ultrathin metasurfaces. We will summarize the fabrication of different holographic recording media and digital holograms based on recent advances in flat meta-optics and nanotechnology. We highlight the rapidly developing field of metasurface holography, presenting the use of multi-functional metasurfaces for multiplexing holography in the use of polarization, wavelength, and incident angle of light. In the scope of holographic applications, we will focus on high bandwidth metasurface holograms that offer the strong sensitivity to the orbital angular momentum of light. At the end, we will provide a short summary of this review article and our perspectives on the future development of the vivid holography field.

The extracellular matrix is a complex system of interacting macromolecules that serve structural and functional purposes to maintain homeostasis of a cell. These systems can interact with external factors and carry signaling molecules across large distances. As such, the extracellular matrix is the center of many interesting components that can be functionalized for industrial purposes and targeted for therapeutic approaches. However, studying these intricate systems in a meaningful way, that improves our understanding of the underlying mechanism, can prove to be a challenge for any one technique. As such, the combination of various techniques, ranging from X-ray crystallography to understand the atomic structures of macromolecules to cell assays covering the functional aspects in a coherent larger characterization, is crucial for an accurate interpretation of the system of interest. The combination of various structural and functional biochemical techniques is often termed the hybrid method approach. The purpose of this work is to demonstrate and further develop the hybrid method approach to the extent where multiple combinations of techniques are utilized to study and understand various extracellular matrix and environment systems. The initial focus using the hybrid method approach is the examination of a surface-layer protein in an archaeal species for the development of nanotube and nanocarrier systems that bind various hydrophobic ligands. It was shown that the nanotube was able to be developed as a passive sampling medium for the monitoring of polycyclic aromatic hydrocarbons and as a nanocarrier system for carborane which is used in boron neutron capture therapies against various types of cancers. The second focus of this work is on mammalian extracellular matrix macromolecular systems and the formation of protein assemblies to study the structural and functional features that are a common source for pathological diseases. Here, the hybrid method approach was

In this work, spin transport in the XXZ model is investigated. As a quantum integrable model the XXZ spin chain contains infinitely many conserved charges. The presence of these conserved charges results in the coexistence of ballistic and diffusive spin transport. Ballistic spin transport is characterized by the spin Drude weight, which was originally derived in 1999 by Zotos. This original derivation was controversial, particularly when divergences were observed in intermediate steps. In this thesis a novel approach for deriving the spin Drude weight demonstrates that Zotos' formula follows from relatively few assumptions. Furthermore, an asymptotic analysis of this formula at infinite temperature was found to be consistent with the Prosen--Ilievski bound, obtained from direct consideration of conserved charges. At low--temperatures a more complicated analysis is carried out to determine the non--analytic temperature correction term. This non--analytic temperature correction was found to give rise to the fractal structure of the Drude weight observed at finite temperatures. The form of this low--temperature correction raises important questions about the applicability of non--linear Luttinger liquid theory to quantum integrable models. Spin transport in the non--linear response framework is also considered in this thesis, where the non--linear Drude weight (NLDW) at infinite temperatures is determined. At infinite temperatures the NLDW is found to have an even more fractal structure than the linear Drude weight due to Bethe string lengths appearing explicitly in the final result. These results suggest that the Bethe strings may be indispensable for understanding spin transport.

This work presents and investigates a novel high-performance antenna design for remote sensing and satellite communications applications that is compact and lightweight. The performance requirements include dual-polarization, wide impedance bandwidth, low cross-polarization, high gain, and high aperture efficiency. To simultaneously achieve all these qualities is challenging and a combination of compatible performance enhancement techniques was selected and derived. A new antenna design, namely an octagonal cavity-backed radiating open prism (OCROP) antenna, was first introduced. The antenna is orthogonally and differentially fed to provide dual-polarization and low cross-polarization. The impedance bandwidth is increased by combining the resonances from the radiating feedlines and the open prism. The corner truncated octagonal ground cavity, instead of a more commonly seen square ground plane or square ground cavity, is used to further suppress the cross-polarization and enhance the gain and aperture efficiency. To show the superiority of the octagonal design, it was compared with a square ground cavity backed antenna. To further improve the gain of this novel antenna, its array and flared configurations are considered, investigated, and compared. The array design offers higher gain and aperture efficiency, while the flared design can provide lower cross-polarization. To achieve higher gain with the flared design, a larger flare angle was chosen which increased cross-polarization. To remedy the problem of the increased cross-polarization, a new iris design concept is proposed and investigated. It shows that this method can successfully suppress the cross-polarization of the flared design. This concept is general and has the potential to be applied to other types of aperture antennas. The design concepts and the simulation results are verified by fabricating and testing two prototypes, i.e., with and without a flare.

Image distortion is one of the most common problems of optical receivers. Adaptive Optics (AO) technology was invented to solve that issue for ground-based telescopes. The deformable mirror (DM) is the corrector which is being used to correct the aberrated received image in an AO system. The arrays of actuators and the flexible mirror face sheet are the two main elements of a DM. In this thesis, a tri-electrode electrostatic actuator was studied which is comprised of one moving MEMS electrode and two fixed controlling electrodes. The actuator is primarily beneficial for usage in an array of actuators for DMs, since only one common high-voltage electrode is employed as the background electrode for all actuators in the array, and the movement of each individual actuator can be controlled by an individual low voltage electrode. The tri-electrode topology, and the additionally presented extended electrode tri-electrode configurations, are designed such that they can be utilized for other applications such as MEMS switches. In this work, all the design parameters of the tri-electrode actuator were studied in simulation using the finite element method and restoring spring force method, as well as experimentally. The design studies were dimensionless. Therefore, the optimizations can be used for an actuator of any size. The studies showed that the controlling voltage of the actuator can be decreased significantly. For one specific design, it was shown that the controlling voltage is almost four times smaller than for a conventional parallel plate electrostatic actuator. The maximum displacement of the actuator can be enhanced significantly compared to that of the conventional configuration. The increased range of motion can be bidirectional, and for one specific case it was 2.5 times larger than for the conventional actuator using the extended electrode design. Two silicon MEMS actuators were designed in order to experimentally verify the simulation studies. The measuremen

Laying hens have an extra demand on calcium (Ca) homeostasis due to egg-laying. The calcium-sensing receptor (CaSR) plays a central role in Ca homeostasis. The thesis aimed to develop effective methods for maintaining desired Ca homeostasis in laying hens. The first study demonstrated that chicken CaSR (cCaSR) and chicken vitamin D receptor (cVDR) are widely distributed in the kidney, gastrointestinal tract, shell gland, and tibia in laying hens at different laying stages. The second study characterized cCaSR ligands in cCaSR-stably expressing HEK293 cells and investigated the binding modes between cCaSR and its ligands. Results showed that L-tryptophan (L-Trp) and inorganic PO43- are cCaSR modulators, acting as positive and negative allosteric modulators, respectively. The third study isolated chicken mesenchymal stem cells (MSCs) from broilers and layers and demonstrated that cCaSR and cVDR were expressed in broiler and layer MSCs. The osteogenic differentiation process in layer MSCs was faster than that in the broiler MSCs. L-Trp and 1,25-dihydroxycholecalciferol (1,25OHD3) were found to regulate proliferation and osteogenic differentiation in broiler and layer MSCs, depending on the modulator’s doses and treatment time. The fourth study was to investigate the interactive effects of Ca and L-Trp, and of Ca and 25-hydroxycholecalciferol (25HyD) substitution for vitamin D3 on egg production, eggshell quality, bone health, and calcium homeostasis in Dekalb layers from 26 to 29 weeks of age. Results showed that increased dietary Trp levels increased serum Ca level, eggshell quality, and tibia traits. An interactive effect was found that Ca continued to increase the relative eggshell weight and eggshell thickness as Trp level increased. However, 25HyD did not improve egg production, eggshell quality, and bone health. Taken together, the cCaSR and cVDR are widely expressed in laying hens. Ca2+ and L-Trp promoted osteogenic differentiation in chicken MSCs and they impro

High power laser sources of ultrashort pulses (~fs, 10-15 s, femtosecond) have numerous applications in science, medicine, and technology such as spectroscopy, optical coherence tomography, microscopy, laser micromachining and processing of materials (e.g., all smartphone glass screens are cut with ultrashort laser pulses). The generation of ultrashort laser pulses requires a laser gain medium to have a broad emission spectrum. Generation of ultrashort pulses with high average power, on the other hand, also requires the gain medium to have good thermal conductivity. These two requirements (i.e., emission spectrum vs thermal conductivity), unfortunately, are contradictory to each other. Broad emission spectra (>30 nm) are generally observed from materials with disordered structure, i.e., glasses, which have poor thermal conductivity (~1W/m/K). Crystals, on the other hand, have good thermal conductivity (~5-10 W/m/K), but narrow emission spectra (<10 nm). At the same time propagation of intense laser pulses induces strong nonlinear optical effects in laser components (laser crystals, lenses, and even in air, etc.) which all should be minimized to avoid pulse spreading in time. Therefore, generation of ultrashort laser pulses with high average power is not a trivial task not only from the material properties point of view, but also from the way that these pulses are generated and stabilized. A method of generation of ultrashort pulses is called mode locking. Fortunately, a new laser crystal, Yb:CALGO, recently became available which has very good spectroscopic and thermal properties, i.e. 50 nm of bandwidth and 6.9 W/m/K of thermal conductivity. The first stage of the work focused on the continuous-wave (CW) operation of the laser. To enhance the lasing efficiency, the intracavity losses were estimated and made sure that this loss was low. After that, the tuning performance of the laser was evaluated using a 12 mm and 24 mm optimized off-surface axis birefringent filte

We test the static Stark shift of the transition from the ground state to the first excited s state in 87Rb, providing an experimental verification of the relativistic many-body calculations of this value performed by Safronova, Johnson, and Derevianko. The experiment is conducted on atoms held in a magneto-optical-trap, using the facility and equipment used for the Francium Parity Non-Conservation Experiment. We describe the equipment including some notes on its use and preparation, the experimental procedure, and the experimental results. We obtain a value of 0.6056 +/- 3.4 X 10^-3 MHz/(kV/cm)^2, giving good experimental agreement with the values calculated for the Stark shift of the 5s to 6s transition by Safronova et al.

The weak interaction is the only fundamental interaction in nature that violates parity symmetry. Parity-violation produces asymmetric outcomes in mirror image experiments. The high-precision asymmetry measurements, using electrons with rapidly flipping polarization as probes, have extraordinary scientific reach across various subfields. PREX-2 and MOLLER are two such experiments that can only be conducted at the state-of-the-art Thomas Jefferson National Accelerator Facility. The asymmetries (A_PV) measured at PREX-2 and MOLLER kinematics (Q^2), can help to estimate the density distributions in neutron-rich matter and search for Physics Beyond the Standard Model respectively. PREX-2 was conducted by scattering a longitudinally polarized 953 MeV electron beam elastically from 208Pb at a ~ 5 degree scattering angle. The measured asymmetry was A_PV = 550±16 [stat.]±8 [sys.] ppb at average Q^2 = 0.00616 GeV^2. Together with PREX-1, it imposes robust constraints on the interior baryon density (0.1480±0.0036 [exp.]±0.0013 [theo.] fm^−3) and the neutron skin (0.283±0.071 fm) of 208Pb. Model correlations between the neutron skin and the nuclear symmetry pressure indicate a stiff symmetry energy near the nuclear saturation density. Together with neutron star observations, it enhances the understanding of exotic matter states. In contrast to PREX-2, MOLLER will operate with an 11 GeV longitudinally polarized electron beam as the flagship experiment utilizing the 12 GeV upgrade at Jefferson Lab. The electrons will be scattered from atomic electrons in a liquid hydrogen target and the scattered electrons will be guided by a novel spectrometer with full azimuthal coverage to an array of quartz Cerenkov detectors. The asymmetry and consequently the weak charge of the electron will be measured to a precision of 2.4% at average Q^2 = 0.0056 GeV^2. The value of the electroweak mixing angle derived from the above measurement can be compared to the Standard Model prediction in search

The goal of this research was to propose and evaluate solutions to four important aspects of adaptive radiation therapy in order to make it more reliable, accurate, and efficient in clinical environment. The first study focused on the evaluation of several deformable image registration algorithms. Results demonstrated that the Dense Anatomical Block Matching registration outperformed the other methods making it a very promising alternative to the existing registration methods for challenging CT-to-CBCT registration and its applications for radiation dose calculation, dose mapping and contour propagation in adaptive radiation therapy (ART) of the pelvic region. The second study focused on the quantitative evaluation of eight proposed adaptive radiation therapy approaches for prostate cancer patients treated with hypofractionated VMAT. The ART strategies included online and offline methods. The comprehensive analysis showed that daily on-line adaptation approaches were the most impactful. The findings of this study provided applicable insights into the selection of the optimal ART strategy, improving the quality of the decision-making process based on the quantitatively evaluated dosimetric benefits. The third study aimed to utilize a deep learning network to automatically contour critical organs on the computed tomography (CT) scans of head and neck cancer patients. Proposed model achieved expert level accuracy and was able to segment 25 critical organs on unseen CT images in approximately 7 seconds per patient. High accuracy and short contouring time allow for the implementation of the model within a clinical ART workflow, which would lead to a significant decrease in the time required to create a new adapted treatment plan. The objective of the fourth study was to use artificial intelligence methods to build a decision making support system that would classify previously delivered plans of brain tumor patients into those that met treatment planning objectives and t

Research into statistical clustering techniques has grown tremendously in the past several years due to advances in both theory and computational capability. Despite this growth, there has been little documented research pertaining to clustering within the context of the casino industry - likely due to the proprietary nature of data. However, clustering results can help identify structure within a given dataset and provide valuable information to stakeholders. In particular, the segmentation of casino patrons may allow casino operators and researchers to develop insight into gambling behaviour and tendencies. Consequently, it is a worthwhile endeavour to explore the application of clustering methods to casino data. First, we discuss in detail several clustering algorithms along with a variety of metrics to assess clustering validity. Next, we apply these algorithms to casino data provided by a local industry partner and compare the resulting partitions. Furthermore, we examine strategies for interpreting these clustering results. Finally, we propose different candidate models which have satisfactory statistical performance and result in meaningful clusters from a pragmatic perspective.

As a new platform for studying light-matter interactions, cavity magnonics has attracted increasing attention in the past decade, because of its promising applications in quantum information processing and spintronics. In such hybrid systems, the strong interaction between cavity photons and ferromagnetic magnons generates cavity magnon polaritons (CMPs), which acquire complementary properties with both the high movability of the microwave photon and the long coherence time of the ferromagnetic spin. On one hand, high movability enables CMP as an excellent information carrier and offers cavity magnonic systems vast ductility. Components with distinct properties can be integrated into the cavity magnonic device to extend its functionality. On the other hand, by taking advantage of the long coherence time, CMP can be a promising candidate to preserve entanglement states in quantum information processing. Based on this versatile platform, technologies have flourished, including gradient memory architecture, single magnon detection, non-local spin current manipulation, and unidirectional invisibility etc. In this thesis, we explore cavity magnonics by designing new cavity magnonic devices based on the dynamics of CMPs. In Chapter 3, we fabricate two cavity magnonic devices with multi-channels. By utilizing the interference between two degenerate channels, a logic gate based on the analogue dynamic Hall effect of CMPs is designed. Additionally, by utilizing the interference between two non-degenerate channels mediated by a magnon mode, a coherent perfect absorber is achieved. In Chapter 4, we introduce the gain mechanism into cavity magnonics and discover the cooperative dynamics of CMPs in a feedback-coupled cavity. Following this work, the electric control of the cooperative dynamics of CMPs is demonstrated. In Chapter 5, we study the photon-magnon interaction in an open system and discover the dissipative photon-magnon coupling effect. To further understand this effec

Time domain spectroscopy with terahertz (THz) pulses is a powerful technique in characterizing material properties. THz technology is still developing and many optical components in this electromagnetic spectrum are not yet so economically available. We construct a THz spectrometer utilizing ultrashort laser pulses in nonlinear crystals that allows phase-resolved detection of light in the bandwidth 0.25-2.25 THz. Using our instrument, we examine spectral features of ordinary low loss materials which are later exploited in the study of multilayered dielectric structures designed to serve as low-cost optics for THz light. We develop wideband antireflection (AR) coatings for a variety of substrates with commercially available films and tapes. Utilizing multilayered structures, we propose the design of an economic, yet efficient, THz linear polarizer. In addition, we designed and constructed distributed Bragg reflectors which are incorporated in building a tunable Fabry-Perot cavity. With the aid of an AR coated electro-optic crystal, high resolution time domain spectroscopy performed on room temperature magnetoelectric multiferroic, BiFeO3 (BFO), showed the presence of electromagnon resonances in the sub-THz range. BFO is a potential material for the study of strong light matter coupling, which can have a substantial technological impact. We have tried tuning the resonances of BFO with applied electric field and optical heating in order to observe polariton modes. Due to the challenges in tuning BFO magnons, we investigate the design aspects of a high Q cavity for the discovery of a hybrid quasiparticle at room temperature, cavity magnon polariton (CMP), in the promising multiferroic. We have performed calculations showing both frequency and time domain response of the empty cavity system to highlight experimental implications for our apparatus. The tools developed in this thesis will be used in the study of CMP in BFO in a future project alongside other research.

Nanoparticles are widely studied systems for a variety of applications; however, as the surface plays the major role in deciding the overall properties, characterization of the surface becomes as important as the characterization of the structure itself. The underlying physics regarding exchange interactions and bonding can be elucidated by studying the structure of the surface and core. Doping allows us to change the overall spin arrangement, and investigate the competition between ferro- and antiferromagnetic interactions. To undertake a rigorous characterization of exchange interactions at the surface and in the core of nanoparticles, I utilize different shapes of Co3O4 and dopings of CuxCo3-xO4 nanoparticles. The antiferromagnetic arrangement of Co3O4 is ideal for studying changes in the magnetism. Due to the competition of ferro- and antiferromagnetic interactions small changes in the exchange can result in large changes in the magnetism. By studying the shapes in the context of the exposed surface planes, differences in the structure of the surface terminations can be correlated to the exchange interactions leading to quantification of the surface exchange and magnetism. On the other hand, by doping Cu into the structure of Co3O4 we can examine the affects that modify the exchange interactions in the core of the particle. The role of Cu becomes extremely important to the exchange interactions creating ligand holes between magnetic ions, facilitating ferromagnetic exchange between the ions. The different shapes, and Cu-doping, allow us to explore the relations between the exchange interactions and the overall magnetism in nanoparticles, where the surface is shown to be directly responsible for differences to the bulk magnetism.

Investigating the environments of galaxies and active galactic nuclei (AGN) is crucial to understanding the formation and evolution of AGN and the host galaxies in which they reside. The environments of galaxies can inform star formation and morphology. The environments of AGN can inform possible accretion scenarios and therefore activity, as well as feedback. Similar environments are expected for the various flavours of AGN as guided by AGN unification. As well, if active galaxies reside in the same environments as passive galaxies, this supports normal galaxies experiencing relatively short periods of activity throughout their lifetimes. We have characterized the environments of a sample of nearby Type I AGN as well as the environments of other active and passive galaxies in the same redshift range. We find a strong similarity between the environments of the reference sample with the comparison AGN and normal galaxies. These results support AGN unification and AGN/galaxy unification where normal galaxies have active periods. We then investigate the environmental dependence for some AGN and host galaxy properties. We find no strong dependence for any parameter over both small scale environment and larger scale environment. This suggests that galaxy and AGN evolution is not sensitive to environment, but is driven by processes within the host galaxy for our sample of optically selected nearby Type I AGN.

The quartz detectors response to 15 MeV to 55 MeV gamma-ray is investigated to understand the contribution of photon background to the MOLLER (Measurement Of a Lepton-Lepton Electroweak Reaction) experiment. The probability of a monoenergetic photon beam interacting with the quartz detector was simulated via the Geant4 Monte Carlo toolkit. The simulation was benchmarked at the Mainz MAMI facility A2 hall using the quartz, LYSO calorimeter, and plastic scintillators. The probability was estimated in terms of efficiency by determining the number of photoelectrons produced per incident photon for each energy. From the simulation, the photoelectron number with the highest efficiency in each energy was compared to the corresponding efficiencies from the experimental data. The experiment results showed higher efficiencies compared to the simulation approximately by a factor of two. Applying the efficiencies which ranged from approximately 1/1000 to 1/250 to the MOLLER main detector plane photon contribution, the background photon contribution is estimated to be below the MOLLER electron rate in the main detector plane. Therefore, the signal from the photon background is expected to be tolerable for the MOLLER experiment and contribute to the precise measurement of the parity-violating asymmetry to a trivial degree.

Wave transport in disordered anisotropic media is investigated experimentally and theoretically. Multiple scattering theory is reviewed, with a focus on the self-consistent theory of localization (SCT). To treat anisotropy, a new version of this theory is adapted to classical waves and extended to finite media. By obtaining analytical results, the two versions of the SCT have been compared in the infinite medium case and found to be in good agreement. Experimentally, the transport is studied via ultrasonic techniques on samples made of brazed elongated aluminium particles oriented in a certain direction. In the diffusive regime, the effect of the anisotropy is to make directions of propagation inside the sample inequivalent. Instead of a single diffusion coefficient, components of a diffusion tensor can be measured in the anisotropic case. Experimental results show good agreement with diffusion theory for two different orientations of the particles. The frequency-independence of the transport anisotropy is demonstrated experimentally for the first time. Using a novel technique to increase the scattering inside the samples, transport regimes for which the diffusion approximation breaks down are reached. In particular, the effect of the anisotropy on the Anderson localization regime is studied. Using transverse confinement experiments, the first experimental observation of the reduction of the transport anisotropy close to the mobility edge is reported for both orientations of the anisotropy. The samples made of these irregular elongated particles also display a slow approach to the localization regime, motivating further experimental work. A theoretical framework based on random matrix theory is used to study the effects of anisotropy on the transport of scalar waves. Introducing correlations such as grouping scatterers by pairs or surrounding scatterers by a spherical exclusion volume results in exotic behaviour compared to the independent scatterers case. The pair

In vivo dosimetry via transmission imaging of the therapy beam can verify the intended treatment plan was delivered to the patient. However, the EPID (electronic portal imaging device) transmission images are contaminated with patient-generated scattered photons. If this component can be accurately estimated, its effect can be removed and therefore the resulting in vivo patient dose estimate will be more accurate. This thesis presents the development of a ‘tri-hybrid’ (TH) algorithm to provide accurate estimates of patient-generated photon scatter at the EPID. The TH method combines three approaches: 1) Analytical methods to solve exactly for singly-scattered photon fluence. 2) For multiply scattered photon fluence, a modified hybrid Monte Carlo (MC) simulation method was applied, using only a few thousand histories. From each second and higher-order interaction site in the MC simulation, energy fluence entering all pixels of the EPID scoring plane was calculated using analytical methods. 3) For the bremsstrahlung and positron annihilation component, a convolution/superposition approach was employed using pre-generated pencil beam scatter kernels superposed on the incident fluence. Since no experimental measurement method is available to directly confirm the separate subcomponents of photon scatter, a Monte Carlo simulation tool was developed to separately score them. This tool was used as the ‘gold standard’ for the development and validation of the TH method. The TH-predicted total patient-scattered photon fluence entering the EPID, as well its energy spectra, are compared with full Monte Carlo simulation (EGSnrc) for validation. A variety of phantoms are tested, including simple slab and anthropomorphic CT, as well as monoenergetic and polyenergetic beams with different field sizes. For these tests, the proposed TH method was demonstrated to be in good agreement with full Monte Carlo simulation, generally within 1%. Parameters of the TH method were optimized to m

Quality control (QC) guidance documents recommend various tests for evaluation of different parameters of x ray imaging systems’ performance. QC tests can be time consuming, user-dependent and require specialized tools. The aim of this thesis is to investigate the noise power spectrum (NPS) as a QC constancy test which is simple, fast and lends itself easily to automated analysis. Uniform images were acquired under different conditions representing deviations from ideal performance using two digital x-ray systems. The stationarity and ergodicity of the noise was assessed. The normalized NPS (NNPS) were calculated using the methodology of the international electrotechnical commission. The total relative difference was used to quantify the changes in the NNPS. The NNPS was computed for images: with focal spot blooming, collected using large and small focal spot (to mimic resolution change), various tube voltage values, with and without defective pixels, with residual image and with a mismatched anti-scatter grid. Results showed that the NPS method is not sensitive to image lag and focal spot blooming investigated in this study. However, the NPS method was sensitive to changes in resolution introduced by changing the focal spot size, kV deviations as small as 1 kV, defective pixels representing 0.01% of the image pixel and 0.98 MSE difference from the original image, affixed pattern artifacts and a mismatched grid. The NPS was decomposed into its components (fixed pattern, quantum and electronic) to investigate the effect of different performance deviations on the NPS components. The negligibility of the electronic noise was verified. The results showed the fixed pattern changes impacted the fixed pattern NPS component the most and the changes associated with quantum noise affected the quantum component. This thesis suggests the NPS is sensitive to a variety of deviations in system parameters and performance metrics likely to arise in the quality control of digital rad

The discovery of dissipative coupling leads to level attraction. It opens a new avenue to study light-matter interaction, enabling novel applications in quantum information and spintronics technologies based on its exotic features. The polaritons raised from spin-photon hybridization display coherence for the exchange of energy. The coherent and dissipative coupling between two resonances have been modeled by two oscillators with different coupling components, with different behaviors in eigenspace. We briefly introduced numerical methods to obtain the field distribution of resonant modes from Maxwell's equations and the time-domain analysis on the coherent and dissipative coupled system. These numerical results help us to enhance our understanding from another perspective and may benefit the future cavity magnonics research in the nonlinear regime. The level attraction is demonstrated on a planar structure by using a cross-shaped microstrip resonator and split-ring resonators. The dissipatively coupled metamaterial has been achieved by compensating the electric and magnetic coupling. Furthermore, the zero dampings in the hybridized system have been proven to be singularities. This system preserves an infinity quality factor and a sharp transition from rigorous zero to unity transmission, which displays promising applications on sensing and switch devices. Based on previous research, the interference between the coherent and dissipative coupling displays a giant nonreciprocity in cavity magnonics. Since the bandwidth of nonreciprocity is limited by the magnon, there remains a challenge of designing broadband nonreciprocal devices for practical applications. By locally control the radiation of magnon, an effective broadband nonreciprocity has been demonstrated with a few hundreds of times of magnon bandwidth. This thesis work improves the understanding of coherent and dissipative coupled systems. Moreover, it explores the approaches to implementing dissipative coupli